In the story, Mr. Zeldin expressed gratitude to Mr. Bannon, former top adviser to President Trump who also campaigned mightily this month for Roy Moore in the Alabama Senate race. Mr. Moore, accused of multiple sexual improprieties involving teenage girls, lost.

For all the many ways Mr. Moore will get his name in the history books, this can also be said: He is likely the only candidate for the U.S. Senate ever said to have been banned from a shopping mall because of his history of trying to pick up teenage girls.

Since the Moore loss, Mr. Bannon has been pilloried by prominent Republicans who consider him toxic to their brand. Mr. Zeldin’s GOP colleague in the House, Congressman Peter King, labeled Bannon a “disheveled drunk,” saying he was a Goldman Sachs millionaire masquerading as a hero to the working man.

Mr. Bannon said in the Breitbart story that he wanted to help with Mr. Zeldin’s fundraiser after House Speaker Paul Ryan pulled out to punish Mr. Zeldin for opposing the House tax bill, which caps deductions for property taxes.

National issues such as the #metoo movement are playing out in the 1st Congressional District, where Mr. Zeldin will presumably run for re-election next fall, when the GOP majority in both the House and Senate will be challenged. Mr. Bannon, with Mr. Zeldin’s approval, has brought his brand here to this district.

Regardless of how 2018 plays out nationally and in Mr. Zeldin’s district, Mr. Bannon is now part of his campaign. Any Democrat — or Republican who wants to challenge him in a primary — will bring up Bannon over and over. Activists supporting the #metoo movement against sexual harassment will do the same.

It is puzzling why Mr. Zeldin would go down this road. In his comments to Breitbart, he made clear his gratitude to Mr. Bannon.

“These are challenging times, under attack by some of the most hate-filled liberal obstructionists in America, all while facing retribution from the Speaker for doing right by my own constituents and state,” Mr. Zeldin is quoted as saying in Breitbart.

He went on to say that last week’s event was “my best fundraiser of the year, an amazing response that I very much appreciate.”

Mr. Zeldin’s supporters will praise him for hanging in there with Mr. Bannon, even as other Republicans run away from him. And his critics will have a field day now that he’s associated himself with a controversial figure and a fierce backer of Roy Moore. It feels like the race for the 1st Congressional District is already underway, with Mr. Zeldin giving his opponents a very strong hand to play.